1. Field of the Invention
The present invention relates to treating metallic substrates, particularly ferrous metal substrates, so as to impart corrosion resistance thereto.
2. Brief Description of the Prior Art
It is well known in the art that chromic acid and phosphating pretreatments can be used to impart corrosion resistance to substrates. Examples of these pretreatments are the phosphating treatments which include iron phosphating, mixed iron and calcium phosphating and zinc phosphating. Such pretreatments may optionally be followed by a chromic acid rinse. The pretreatment operations, although employed on many industrial electrodeposition lines, are undesirable for a number of reasons. First of all, pretreatments are expensive. Besides the cost of the chemicals themselves, a considerable capital investment is required for equipment. In addition, pretreatments cause pollution problems, the solutions of which add to their expense. Also known in the art are onium salts of monomers and polymers which can be used to pretreat metallic substrates to impart corrosion resistance.
The present invention relates to the reaction products of a beta-diketone and an epoxy material which are blended with monomeric or polymeric phosphonium salts. The products are useful for the preparation of compositions which impart excellent corrosion resistance properties to substrates treated therewith.
Reference is hereby made to commonly assigned Ser. No. 193,046, filed even date herewith entitled "Beta-Diketone-Epoxy Resin Reaction Products Useful for Providing Corrosion Resistance".